Four elements earn permanent seats on the periodic table

U.S., Russian and Japanese scientists credited with official discoveries

FEWER U’S The official discovery of elements 113, 115, 117 and 118 means that all 118 elements in the periodic table’s first seven rows have been found on Earth or produced in the lab. The four new elements will soon get names replacing the temporary “Uu” placeholder names.

E. Otwell

The seventh row of the periodic table is officially full.

On December 30, the International Union of Pure and Applied Chemistry announced that a Russian-U.S. collaboration had attained sufficient evidence to claim the discovery of elements 115, 117 and 118. IUPAC awarded credit for the discovery of element 113 to scientists at RIKEN in Wako, Japan (SN Online: 9/27/12). Both groups synthesized the elements by slamming lighter nuclei into each other and tracking the decay of the radioactive superheavy elements that followed.

This article is available only to subscribing members. Join the Society today or Log in.